So i bought one when they first came out for my HTC s5 with the adapters to fit my optics. The next phone i got obviously wasn't gonna work and the new case was $50, im cheap so i bought a cheap case for $5 and cut the eye piece off of the original phoneskope case leaving a good amount of surface area and lined it up over the camera slot on the new phone case and super glued it down. Its not the prettiest but it gets the job done. I have done this probably 5 times now. Lol.
Side note, while at the hunting expo the first or second year they came out while I was at there booth I overheard a conversation between a phonskope guy and someone else, he said it costs them about .50 cents to make a case, at the time they was selling them for $50. Just thought that was interesting.